If you've set DW to recognize TPL as an extension, you should add it here to the doctypes attribute.

2. Add a Smarty scheme to CodeColoring.xml. There is one attached below. To add it, just paste the attached file somewhere between the <codeColoring> </codeColoring> tags, after one of the existing <scheme> </scheme> elements.

If you want to set up your own Smarty colors, I believe it's possible to edit them within DW from a preferences menu somewhere. Or, you can dive into Colors.xml.

A caveat: DW installs "personal" copies of some of the config files in \Documents and Settings\<user>\Application Data\Macromedia\Dreamweaver MX\Configuration\...

These settings will _override_ the ones found in DW's Configuration directory, so change these files instead (and take a backup before doing so).